From the Wikipedia page [1] Deans Brook is a stream which runs between Mill Hill and Edgware in the London Borough of Barnet. It is a tributary of the Silk Stream, which is a tributary of the River Brent, which is a tributary of the River Thames. The brook rises on Mill Hill Golf Course,, and passes through a culvert under the M1 motorway to Stoneyfields Park, where it is dammed to form an ornamental lake. It then passes through suburban Edgware, where is combines with the Edgware Brook to become the Silk Stream near Edgware Hospital.